The present invention pertains to molded plastic parts for attachment to a supporting member. More specifically, the present invention relates to clip house mounting structures which provide improved flexural characteristics and structural strength in the corresponding part.
Injection molded plastic parts are commonly used in the automotive industry for side panels, spoilers, dashboards, armrests, wheel covers, filler panels, trim pieces, bumpers, side-sill garnishes, rocker panels and the like. Typically these parts are provided with a painted, or other decorative surface such as by means of film lamination techniques. In film lamination techniques, a paint film laminate is co-molded over an external show face surface of the plastic part. The film laminate is typically pre-formed, inserted into a mold cavity, and a thermoplastic resin is injected under pressure into the mold cavity against the backside of the laminate. The result is a plastic part having a film laminate co-molded over a plastic substrate. Laminated paint films are detailed in U.S. Pat. No. 5,514,427, the entire disclosure of which is incorporated by reference herein. Techniques for preforming paint film laminates and insert molding film-plastic parts are disclosed in U.S. Pat. No. 5,599,608, the disclosure of which is incorporated herein by reference.
The plastic parts are typically provided with a series of integrally molded attachment means or as they are referred to in the art “clip houses” for securing the part to the given support member. Structural strength of the attachment means is dependent upon many factors including the thickness of the plastic at the intersection of the attachment means with the part to be supported.
One representative mounting structure for an automotive part is shown in U.S. Pat. No. 6,171,543. In this disclosure, a reinforcing rib is interposed between the connection of the clip house structure and the hidden side of the corresponding plastic part. The rib provides the required strength while limiting the thickness of plastic material proximate the show face surfaces of the part.
Some elongated injection molded automobile parts, such as a rocker panel and side sill garnishes, comprise a top show surface connected to a depending side show surface. In these structures, it is desirable to increase the stability of the side show surface while providing increased flex in the top show surface so that the latter can accommodate weight loads that may be exerted thereon such as by passengers who enter and disembark from the vehicle.